diff --git a/src/Twilio/Http/Request.cs b/src/Twilio/Http/Request.cs
index 5d3bd21ef..e0a220fbb 100644
--- a/src/Twilio/Http/Request.cs
+++ b/src/Twilio/Http/Request.cs
@@ -3,6 +3,7 @@
 using System.Linq;
 using System.Text;
 using Twilio.Rest;
+using Twilio.Types;
 
 #if !NET35
 using System.Net;
@@ -66,6 +67,13 @@ public class Request
         /// </summary>
         public List<KeyValuePair<string, string>> HeaderParams { get; private set; }
 
+#if !NET35
+        /// <summary>
+        /// Files to upload
+        /// </summary>
+        public List<KeyValuePair<string, IUploadFile>> Files { get; private set; }
+#endif
+
         /// <summary>
         /// Create a new Twilio request
         /// </summary>
@@ -78,6 +86,9 @@ public Request(HttpMethod method, string url)
             QueryParams = new List<KeyValuePair<string, string>>();
             PostParams = new List<KeyValuePair<string, string>>();
             HeaderParams = new List<KeyValuePair<string, string>>();
+#if !NET35
+            Files = new List<KeyValuePair<string, IUploadFile>>();
+#endif
         }
 
         /// <summary>
@@ -91,6 +102,7 @@ public Request(HttpMethod method, string url)
         /// <param name="postParams">Post data</param>
         /// <param name="edge">Twilio edge</param>
         /// <param name="headerParams">Custom header data</param>
+        /// <param name="files">List of files to upload</param>
         public Request(
             HttpMethod method,
             Domain domain,
@@ -100,6 +112,9 @@ public Request(
             List<KeyValuePair<string, string>> postParams = null,
             string edge = null,
             List<KeyValuePair<string, string>> headerParams = null
+#if !NET35
+            , List<KeyValuePair<string, IUploadFile>> files = null
+#endif
         )
         {
             Method = method;
@@ -110,6 +125,9 @@ public Request(
             QueryParams = queryParams ?? new List<KeyValuePair<string, string>>();
             PostParams = postParams ?? new List<KeyValuePair<string, string>>();
             HeaderParams = headerParams ?? new List<KeyValuePair<string, string>>();
+#if !NET35
+            Files = files ?? new List<KeyValuePair<string, IUploadFile>>();
+#endif
         }
 
         /// <summary>
diff --git a/src/Twilio/Http/SystemNetHttpClient.cs b/src/Twilio/Http/SystemNetHttpClient.cs
index 6ba171f79..1950fabc0 100644
--- a/src/Twilio/Http/SystemNetHttpClient.cs
+++ b/src/Twilio/Http/SystemNetHttpClient.cs
@@ -61,7 +61,31 @@ public override async Task<Response> MakeRequestAsync(Request request)
             var httpRequest = BuildHttpRequest(request);
             if (!Equals(request.Method, HttpMethod.Get))
             {
-                httpRequest.Content = new FormUrlEncodedContent(request.PostParams);
+                if (request.Files.Count > 0)
+                {
+                    var boundary = "---------" + Guid.NewGuid().ToString().ToLower();
+                    var multiPartContent = new MultipartFormDataContent(boundary);
+                    multiPartContent.Headers.ContentType = new MediaTypeHeaderValue("multipart/form-data")
+                    {
+                        Parameters = { new NameValueHeaderValue("boundary", boundary) }
+                    };
+
+                    foreach (var postParam in request.PostParams)
+                    {
+                        multiPartContent.Add(new StringContent(postParam.Value), postParam.Key);
+                    }
+
+                    foreach (var file in request.Files)
+                    {
+                        multiPartContent.Add(new StreamContent(file.Value.Stream), file.Key, file.Value.FileName);
+                    }
+
+                    httpRequest.Content = multiPartContent;
+                }
+                else
+                {
+                    httpRequest.Content = new FormUrlEncodedContent(request.PostParams);
+                }
             }
 
             this.LastRequest = request;
diff --git a/src/Twilio/Rest/Domain.cs b/src/Twilio/Rest/Domain.cs
index 2a6783bfa..316976972 100644
--- a/src/Twilio/Rest/Domain.cs
+++ b/src/Twilio/Rest/Domain.cs
@@ -33,6 +33,7 @@ public static implicit operator Domain(string value)
         public static readonly Domain Monitor = new Domain("monitor");
         public static readonly Domain Notify = new Domain("notify");
         public static readonly Domain Numbers = new Domain("numbers");
+        public static readonly Domain NumbersUpload = new Domain("numbers-upload");
         public static readonly Domain Preview = new Domain("preview");
         public static readonly Domain Pricing = new Domain("pricing");
         public static readonly Domain Proxy = new Domain("proxy");
diff --git a/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentOptions.cs b/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentOptions.cs
index 826278492..f421cbc56 100644
--- a/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentOptions.cs
+++ b/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentOptions.cs
@@ -6,6 +6,7 @@
 using System;
 using System.Collections.Generic;
 using Twilio.Base;
+using Twilio.Types;
 using Twilio.Converters;
 
 namespace Twilio.Rest.Numbers.V2.RegulatoryCompliance
@@ -29,6 +30,10 @@ public class CreateSupportingDocumentOptions : IOptions<SupportingDocumentResour
         /// </summary>
         public object Attributes { get; set; }
 
+#if !NET35
+        public IUploadFile File { get; set; }
+#endif
+
         /// <summary>
         /// Construct a new CreateSupportingDocumentOptions
         /// </summary>
diff --git a/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentResource.cs b/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentResource.cs
index 8fde239ea..a7a97840a 100644
--- a/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentResource.cs
+++ b/src/Twilio/Rest/Numbers/V2/RegulatoryCompliance/SupportingDocumentResource.cs
@@ -40,6 +40,20 @@ public static implicit operator StatusEnum(string value)
 
         private static Request BuildCreateRequest(CreateSupportingDocumentOptions options, ITwilioRestClient client)
         {
+#if !NET35
+            if (options.File != null)
+            {
+                return new Request(
+                    HttpMethod.Post,
+                    Rest.Domain.NumbersUpload,
+                    "/v2/RegulatoryCompliance/SupportingDocuments",
+                    postParams: options.GetParams(),
+                    headerParams: null, 
+                    files: new List<KeyValuePair<string, IUploadFile>> { new KeyValuePair<string, IUploadFile>("File", options.File) }
+                );
+            }
+#endif
+
             return new Request(
                 HttpMethod.Post,
                 Rest.Domain.Numbers,
@@ -63,7 +77,7 @@ public static SupportingDocumentResource Create(CreateSupportingDocumentOptions
             return FromJson(response.Content);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Create a new Supporting Document.
         /// </summary>
@@ -77,7 +91,7 @@ public static async System.Threading.Tasks.Task<SupportingDocumentResource> Crea
             var response = await client.RequestAsync(BuildCreateRequest(options, client));
             return FromJson(response.Content);
         }
-        #endif
+#endif
 
         /// <summary>
         /// Create a new Supporting Document.
@@ -96,7 +110,7 @@ public static SupportingDocumentResource Create(string friendlyName,
             return Create(options, client);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Create a new Supporting Document.
         /// </summary>
@@ -113,7 +127,7 @@ public static async System.Threading.Tasks.Task<SupportingDocumentResource> Crea
             var options = new CreateSupportingDocumentOptions(friendlyName, type){Attributes = attributes};
             return await CreateAsync(options, client);
         }
-        #endif
+#endif
 
         private static Request BuildReadRequest(ReadSupportingDocumentOptions options, ITwilioRestClient client)
         {
@@ -142,7 +156,7 @@ public static ResourceSet<SupportingDocumentResource> Read(ReadSupportingDocumen
             return new ResourceSet<SupportingDocumentResource>(page, options, client);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Retrieve a list of all Supporting Document for an account.
         /// </summary>
@@ -158,7 +172,7 @@ public static async System.Threading.Tasks.Task<ResourceSet<SupportingDocumentRe
             var page = Page<SupportingDocumentResource>.FromJson("results", response.Content);
             return new ResourceSet<SupportingDocumentResource>(page, options, client);
         }
-        #endif
+#endif
 
         /// <summary>
         /// Retrieve a list of all Supporting Document for an account.
@@ -175,7 +189,7 @@ public static ResourceSet<SupportingDocumentResource> Read(int? pageSize = null,
             return Read(options, client);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Retrieve a list of all Supporting Document for an account.
         /// </summary>
@@ -190,7 +204,7 @@ public static async System.Threading.Tasks.Task<ResourceSet<SupportingDocumentRe
             var options = new ReadSupportingDocumentOptions(){PageSize = pageSize, Limit = limit};
             return await ReadAsync(options, client);
         }
-        #endif
+#endif
 
         /// <summary>
         /// Fetch the target page of records
@@ -272,7 +286,7 @@ public static SupportingDocumentResource Fetch(FetchSupportingDocumentOptions op
             return FromJson(response.Content);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Fetch specific Supporting Document Instance.
         /// </summary>
@@ -286,7 +300,7 @@ public static async System.Threading.Tasks.Task<SupportingDocumentResource> Fetc
             var response = await client.RequestAsync(BuildFetchRequest(options, client));
             return FromJson(response.Content);
         }
-        #endif
+#endif
 
         /// <summary>
         /// Fetch specific Supporting Document Instance.
@@ -300,7 +314,7 @@ public static SupportingDocumentResource Fetch(string pathSid, ITwilioRestClient
             return Fetch(options, client);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Fetch specific Supporting Document Instance.
         /// </summary>
@@ -313,7 +327,7 @@ public static async System.Threading.Tasks.Task<SupportingDocumentResource> Fetc
             var options = new FetchSupportingDocumentOptions(pathSid);
             return await FetchAsync(options, client);
         }
-        #endif
+#endif
 
         private static Request BuildUpdateRequest(UpdateSupportingDocumentOptions options, ITwilioRestClient client)
         {
@@ -340,7 +354,7 @@ public static SupportingDocumentResource Update(UpdateSupportingDocumentOptions
             return FromJson(response.Content);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Update an existing Supporting Document.
         /// </summary>
@@ -354,7 +368,7 @@ public static async System.Threading.Tasks.Task<SupportingDocumentResource> Upda
             var response = await client.RequestAsync(BuildUpdateRequest(options, client));
             return FromJson(response.Content);
         }
-        #endif
+#endif
 
         /// <summary>
         /// Update an existing Supporting Document.
@@ -373,7 +387,7 @@ public static SupportingDocumentResource Update(string pathSid,
             return Update(options, client);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Update an existing Supporting Document.
         /// </summary>
@@ -390,7 +404,7 @@ public static async System.Threading.Tasks.Task<SupportingDocumentResource> Upda
             var options = new UpdateSupportingDocumentOptions(pathSid){FriendlyName = friendlyName, Attributes = attributes};
             return await UpdateAsync(options, client);
         }
-        #endif
+#endif
 
         private static Request BuildDeleteRequest(DeleteSupportingDocumentOptions options, ITwilioRestClient client)
         {
@@ -416,7 +430,7 @@ public static bool Delete(DeleteSupportingDocumentOptions options, ITwilioRestCl
             return response.StatusCode == System.Net.HttpStatusCode.NoContent;
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Delete a specific Supporting Document.
         /// </summary>
@@ -430,7 +444,7 @@ public static async System.Threading.Tasks.Task<bool> DeleteAsync(DeleteSupporti
             var response = await client.RequestAsync(BuildDeleteRequest(options, client));
             return response.StatusCode == System.Net.HttpStatusCode.NoContent;
         }
-        #endif
+#endif
 
         /// <summary>
         /// Delete a specific Supporting Document.
@@ -444,7 +458,7 @@ public static bool Delete(string pathSid, ITwilioRestClient client = null)
             return Delete(options, client);
         }
 
-        #if !NET35
+#if !NET35
         /// <summary>
         /// Delete a specific Supporting Document.
         /// </summary>
@@ -456,7 +470,7 @@ public static async System.Threading.Tasks.Task<bool> DeleteAsync(string pathSid
             var options = new DeleteSupportingDocumentOptions(pathSid);
             return await DeleteAsync(options, client);
         }
-        #endif
+#endif
 
         /// <summary>
         /// Converts a JSON string into a SupportingDocumentResource object
diff --git a/src/Twilio/Types/UploadFile.cs b/src/Twilio/Types/UploadFile.cs
new file mode 100644
index 000000000..6f9d0faff
--- /dev/null
+++ b/src/Twilio/Types/UploadFile.cs
@@ -0,0 +1,24 @@
+#if !NET35
+using System.IO;
+
+namespace Twilio.Types
+{
+    public interface IUploadFile
+    {
+        string FileName { get; }
+        Stream Stream { get; }
+    }
+
+    public class UploadFile: IUploadFile
+    {
+        public UploadFile(string fileName, Stream stream)
+        {
+            FileName = fileName;
+            Stream = stream;
+        }
+
+        public string FileName { get; private set; }
+        public Stream Stream { get; private set; }
+    }
+}
+#endif
\ No newline at end of file
diff --git a/test/Twilio.Test/Http/SystemNetHttpClientTest.cs b/test/Twilio.Test/Http/SystemNetHttpClientTest.cs
index 9f7117ac1..54c6f2733 100644
--- a/test/Twilio.Test/Http/SystemNetHttpClientTest.cs
+++ b/test/Twilio.Test/Http/SystemNetHttpClientTest.cs
@@ -9,6 +9,7 @@
 using System.Text.RegularExpressions;
 using NUnit.Framework;
 using Twilio.Http;
+using Twilio.Types;
 using HttpMethod = Twilio.Http.HttpMethod;
 
 namespace Twilio.Tests.Http
@@ -25,6 +26,7 @@ public class MockResponse
         private Dictionary<String, MockResponse> responseMap = new Dictionary<String, MockResponse>();
 
         public HttpRequestMessage InternalRequest { get; private set; }
+        public List<HttpContent> InternalRequestNestedContent { get; private set; }
 
         private Random random = new Random();
 
@@ -61,6 +63,11 @@ protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage reques
                 throw response.error;
             }
             this.InternalRequest = request;
+            
+            if (request.Content is IEnumerable<HttpContent> nestedContent)
+            {
+                this.InternalRequestNestedContent = nestedContent.ToList();
+            }
 
             // Inject some randomness for multi-threading scenarios. And for fun!
             Thread.Sleep(random.Next(100));
@@ -219,6 +226,36 @@ public void TestMakeRequestWithParams()
             Assert.IsInstanceOf<FormUrlEncodedContent>(internalRequest.Content);
         }
 
+        [Test]
+        public void TestMakeRequestWithParamsAndFile()
+        {
+            this._mockHttp.Respond("https://api.twilio.com/v1/Resource.json", HttpStatusCode.OK);
+
+            Request testRequest = new Request(HttpMethod.Post, "https://api.twilio.com/v1/Resource.json");
+            testRequest.AddPostParam("post_param", "post_value");
+            testRequest.AddQueryParam("query_param", "query_value");
+
+            UploadFile file = new UploadFile("FileName.txt", new System.IO.MemoryStream(System.Text.Encoding.UTF8.GetBytes("File content")));
+            testRequest.Files.Add(new KeyValuePair<string, IUploadFile>("File", file));
+
+            this.TwilioHttpClient.MakeRequest(testRequest);
+
+            HttpRequestMessage internalRequest = this._mockHttp.InternalRequest;
+            List<HttpContent> nestedRequestContent = this._mockHttp.InternalRequestNestedContent;
+
+            Assert.AreEqual("https://api.twilio.com/v1/Resource.json?query_param=query_value",
+                            internalRequest.RequestUri.ToString());
+
+            Assert.IsNotNull(internalRequest.Content);
+            Assert.IsInstanceOf<MultipartFormDataContent>(internalRequest.Content);
+
+            Assert.IsNotNull(nestedRequestContent);
+            Assert.AreEqual(2, nestedRequestContent.Count);
+
+            Assert.IsInstanceOf<StringContent>(nestedRequestContent[0]);
+            Assert.IsInstanceOf<StreamContent>(nestedRequestContent[1]);
+        }
+
         [Test]
         public void TestMakeRequestAddsHeadersAndUserAgent()
         {